This is a great list put together by Vicki Mindman, a gust blogger over at Tech Learning. Tech&Learning is a great site for educational resources, discussions and product reviews all around the idea of integrating technology in the classroom. Be sure to sign up for their Tech Learning Digital Magazine - it has articles, profiles and how to material as well as information on the latest tech developments in education.
There are quite a few free observation and data apps but you must commit to their software to sync your data. Examples include: Ecove, Stride walkthrough, RANDA, Observation 360,OASYS.